1. Field of Invention
The present invention relates to hydrometers and more particularly to an electronic hydrometer having an electronic circuit capable of automatically controlling the position of a float by means of a variable current supply and providing an output signal indicative of the density of a liquid.
2. Description of Prior Art
Various hydrometer constructions are known. The present invention utilizes an electronic hydrometer with a permanent magnet wherein the current flowing through the force coil is utilized to displace the float to restore to a neutral position. U.S. Pat. No. 3,964,317 does utilize a permanent magnet in combination with the float. However, the device operates in a different manner than the present invention wherein the current generated by the circuit associated with the coil generates heating losses corresponding to the difference between the density of the liquid and the density corresponding to a neutral buoyancy position of the float. The construction of the hydrometer and electronic circuit of this patent is quite different from that of the present invention although there are similarities in the use of a permanent magnet, but the sensor and the electronic circuit operate entirely differently from that of the present invention.